Objectives:In recent years, composite scaffolds made ofpolymers and bioactive ceramics have foundnumerous applications in bone tissue engineering dueto their superior properties. Among various polymers, chitosan (Cs) and gelatin (Gel) gained more attention because of their desirable properties. In this study, by using these two polymers and hydroxyapatite (HA) which resembles inorganic phase of human bone, three-dimensional composite scaffolds were preparedby freeze-drying method andbehavior of osteoblast cells on them was evaluated.Thisstudy aimed at preparing an appropriate bioactive scaffold for bone tissue engineering.

Materials and Methods: In order to evaluatethe effect ofgelatin concentration onbiological propertiesof scaffolds, three different concentrations of gelatin (0,10, and 20%) were added to composite scaffolds.Forassessment of thebiological properties of scaffolds, osteoblast cells were cultured on the composite scaffolds and their behavior was monitored.Scanning electron microscopy (SEM)analysis and alkaline phosphatase activity (ALP)testwerecarried out to assess the mentioned factors.

Results: SEM analysis showed high cell attachment and proliferation on the scaffolds. Alkaline phosphatase activity of osteoblast cells indicated the suitability of composite scaffolds containing a higher concentration of gelatincompared to otherconcentrationsas well as overallhigh activity of osteoblast cells on all scaffolds.